As is well known, most of the batch-freezer machines that are normally used for producing homemade ice-cream, are provided with a processing tank of a substantially cylindrical shape that extends horizontally inside the machine, starting from the front facing wall of the machine; with a closing hatch that is hinged on the front facing wall of the machine so as to rotate around a vertical axis to and from an operating position in which it closes the opening of the fluid-tight processing tank; with an internal refrigerating system that is adapted to bring and maintain the processing tank and its contents to a temperature usually between −10° C. and −35° C.; and with a rotating mixing member that is mounted in an axially rotatable manner inside the processing tank, so as to be able to continuously blend and then mix the semi-solid mixture that forms inside the processing tank during the cooling of the processing tank, so as to obtain homemade ice-cream.
The ingredients necessary to produce the ice-cream are poured inside the processing tank through a hopper specifically made on the upper portion of the closing hatch, while the ice-cream is extracted from the processing tank through a discharge outlet with manual opening and closing which is usually arranged on the lower portion of the closing hatch, using the driving force of the mixing member.
In most horizontal axis batch-freezer machines currently on the market, the mixing member is constituted by a rigid body substantially in the shape of a cylindrical cage, which is inserted in a removable and axially rotatable manner inside the processing tank, and extends coaxial with a reference axis which, in use, is coincident with the longitudinal axis of the processing tank.
More in detail, in most horizontal axis batch-freezer machines currently on the market, the mixing member is composed of two supporting hubs that are arranged immediately next to the two axial ends of the processing tank, both locally coaxial to the longitudinal axis of the tank; and of a series of longitudinal scraping blades that are angularly equally spaced around the longitudinal axis of the processing tank, and extend substantially tangent to the internal cylindrical surface of the processing tank, roughly the entire length of the processing tank, so as to rigidly connect/join one with the other.
The supporting hub which is arranged behind the bottom of the processing tank, is usually provided with a coupling pin that projects cantilevered towards the bottom of the processing tank while remaining locally coaxial to the longitudinal axis of the tank, and is structured so to engage in an angularly rigid way, within a rotating bushing that is arranged on the bottom of the processing tank coaxial to the longitudinal axis of the tank, and is driven in rotation by an electric motor arranged outside the tank.
Generally the scraping blades are instead wound around the longitudinal axis of the tank in a helical movement, while remaining locally substantially tangent to the internal cylindrical surface of the processing tank, and are connected directly to the two supporting hubs so as to form a kind of screw that, by rotating inside the processing tank, is able to remove/scrape the ice-cream from the tank wall and at the same time push the ice-cream towards the front closing hatch.